JP5266961B2 - Manufacturing method of color filter substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such a problem that the retardation of a color filter (CF) fabricated on a transparent substrate is wavy because of influences of multiple interferences in the CF with respect to wavelengths, and thereby, the retardation is not enough as a basic data for calculating a three-dimensional refractive index at each wavelength or the wavelength dependence. <P>SOLUTION: A transparent substrate having a reflectance as low as possible from the CF is used, on which linearly polarized light is allowed to be incident perpendicular to the substrate to obtain the optical axis within the plane of the thin film (a layer in the CF); monochromatic polarized light propagating within a plane including the optical axis and perpendicular to the CF is allowed to be incident to the thin film at a plurality, at least three, of incident angles &phiv;i, to obtain the corresponding retardation R(&phiv;i); a calculation formula R(&phiv;i;n<SB>x</SB>, n<SB>y</SB>, n<SB>z</SB>, &beta;) for the three-dimensional refractive index is determined; and the three-dimensional refractive index of the CF is determined by obtaining nx, ny, nz and &beta; by using the above retardation R (&phiv;i) and the calculation formula R so as to minimize (R(&phiv;i)-R(&phiv;i;n<SB>x</SB>, n<SB>y</SB>, n<SB>z</SB>, &beta;))<SP>2</SP>. The CF substrate has a CF layer having a retardation controlled to -20 to 50 nm by using the above value. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a color filter substrate used in a color liquid crystal display device, and more particularly to a color filter substrate in which a retardation value in a thickness direction of a color filter is precisely controlled.

  The liquid crystal display device is a display element that utilizes the birefringence of liquid crystal molecules, and includes a liquid crystal cell, a polarizing element, and an optical compensation layer. Liquid crystal display devices are roughly classified into two types according to the type of light source: a transmissive type having a light source inside and a reflective type having a structure using an external light source. The transmissive liquid crystal display device has a configuration in which two polarizing elements are attached to both sides of a liquid crystal cell, and one or two optical compensation layers are disposed between the liquid crystal cell and the polarizing element. In the reflective liquid crystal display device, the reflector, the liquid crystal cell, one optical compensation layer, and one polarizing element are arranged in this order. In a liquid crystal cell, rod-like liquid crystal molecules sandwiched between two substrates are aligned and sealed, and a rod-like liquid crystal is formed by applying a voltage to the electrode layers disposed on both sides or one side of the opposing substrate inner surface. This is a mechanism for switching light transmission / light-shielding by changing the orientation state of the active molecule.

  In recent years, liquid crystal display devices have been evaluated for their space-saving, light-weight, and power-saving properties due to their thinness, and at the same time they are rapidly expanding as televisions, and at the same time display performance such as brightness, contrast, and visibility in all directions. There is a strong demand for higher levels.

In response to such demands, it is necessary to further optimize the birefringence of optical elements such as optical compensation layers and color filters used in liquid crystal display devices in accordance with the liquid crystal display mode. In particular, various optical compensation layers have been proposed. For example, in an IPS (In Plane Switching) mode liquid crystal display device having good display characteristics in a high viewing angle range, a three-dimensional main refractive index is proposed. n _x, n _y, with respect to n _z, biaxial retardation film having a refractive index ellipsoid of n _x ≧ n _y ≧ n _z is used (e.g., see non-Patent Document 1). In addition, two biaxial λ / 2 wavelength plates with different _nz sizes are used to compensate for each other's wavelength dispersion, thereby reducing the light leakage in the visible light region in black display and reducing the field of view. An angular IPS liquid crystal display device is disclosed (for example, see Non-Patent Document 2).

Further, it has been found that the birefringence of the color filter affects the visibility of the liquid crystal display device, and the thickness direction retardation Rth for each of the red color pixel, the green color pixel, and the blue color pixel constituting the color filter. Must be precisely controlled (see, for example, Patent Document 1). Here, Rth _{is, Rth = {(n x +} n y) / 2-n z} is a numerical value defined by × d, n _x is a refractive index in the x-direction in the plane of the color pixel layer, n _y represents the refractive index in the y direction in the plane of the colored pixel layer, and _nz represents the refractive index in the thickness direction of the colored pixel layer. Here, n _x is the slow axis of the n _x ≧ n _y, d is the thickness of the color pixel layer (nm).

  Usually, the absolute value of the birefringence of the color filter is 0.01 or less. Further, it is desirable that the thickness direction retardation value of the red colored pixel, the green colored pixel, and the blue colored pixel is as close to 0 as possible. However, the color filter has a wavelength dispersibility such as a constituent member other than the color filter, such as a TAC film. When combined with a certain member, there may be an optimum value other than Rth of substantially zero. In such a case, it is necessary to accurately determine the refractive index.

As an apparatus for measuring the birefringence of an optical element such as an optical compensation layer or a color filter, for example, Rth, the sample is detected by detecting a polarization state when light is transmitted through the sample or reflected on the surface thereof. Various devices such as birefringence measuring devices that measure the anisotropy, optical constants, etc., and devices called transmission polarimetry by the photoelastic modulation method are commercially available, and those that suit the intended use are used. can do. (For example, refer to Patent Documents 2 and 3).

Using the above measurement apparatus, the refractive index or birefringence of an optical element used in a liquid crystal display device or the like is only in a plane perpendicular to the optical element (hereinafter referred to as a sample for simplicity). In recent years, it has become important to accurately evaluate and manage the state in which light is transmitted from various directions, and the three-dimensional refractive index of the optical element (three orthogonal axes of the refractive index ellipsoid). length of: n _x, n _y, it is required to n _z) accurately measured.

  Usually, as a method for obtaining a three-dimensional refractive index, a method is employed in which a sample is cut in three orthogonal directions and the refractive index or birefringence in each plane is measured. At least one layer is formed on a transparent substrate. In the case of a sample in which the above thin film is formed, particularly a retardation film used as an optical compensation layer and an optical element such as a color filter, it is possible to produce a plate-like solid sample in such three orthogonal directions. It is extremely difficult.

  Therefore, for an optical element for a liquid crystal display device, it is necessary to directly measure the thin film on the transparent substrate as it is and evaluate the three-dimensional refractive index under an appropriate approximation. A serious problem arises in that multiple interference occurring between the transparent substrate and the thin film affects the measurement result.

  Hereinafter, this point will be described. First, the suitability of the multiple reflection theory for a multilayer film will be described.

As shown in FIG. 1, there is a thin film 2 having a thickness d ₁ and a refractive index n ₁ = n ₁ −ik ₁ on a substrate 1 having a thickness d ₂ and a refractive index n ₂ = n ₂ −ik ₂ . If light is incident from a medium having a refractive index n _{0 at} an incident angle φ ₀ (part 3 in the figure), then a component (p component) parallel to the incident surface of the electric vector of the incident light (p component) and a perpendicular component ( The amplitude reflectances R _p and R _s and the transmittances T _p and T _{s with} respect to the s component) are expressed by the following formula (3) in consideration of multiple reflection (portion 4 in the figure) inside the film. Generally known (see, for example, Non-Patent Document 3).

式３及び図１におけるｒ₁、ｔ₁およびｒ₂、ｔ₂は、それぞれ媒質／膜および膜／基板境界面における反射および透過のフレネル係数であり、反射のフレネル係数は

In Equation 3 and FIG. 1, r ₁ , t ₁ and r ₂ , t ₂ are the Fresnel coefficients of reflection and transmission at the medium / film and film / substrate interfaces, respectively.

ただし、

However,

透過のフレネル係数は反射のフレネル係数を用いて、

The Fresnel coefficient of transmission is calculated using the Fresnel coefficient of reflection.

で表される。λは真空中での光の波長、φ１、φ２は膜および基板内における屈折角で、Ｓｎｅｌｌの法則より、

It is represented by λ is the wavelength of light in vacuum, φ1 and φ2 are refraction angles in the film and substrate, and from Snell's law,

で表わされる複素数である。
したがって、原理的には、反射率Ｒｐ、Ｒｓ、透過率Ｔｐ、Ｒｓの測定を未知の変数分だけ行い、連立方程式を解くことによって多重干渉を取り込んだ近似を含まない３次元屈折率ｎ₁，ｎ₂等を求めることができるはずであるが、この連立方程式を解くことは実際上容
易ではなく現実的には不可能である。ここで、ｎ₁，ｎ₂は、特に断らない限り複素屈折率を指すものとする。

It is a complex number represented by
Therefore, in principle, the reflectance Rp, Rs, transmittance Tp, performs measurement of Rs only unknown variable component, three-dimensional refractive index n ₁ that does not include the approximate incorporating multiple interference by solving the simultaneous equations, it should be possible to obtain the n _2, etc., but it is impossible in practice not easy in practice to solve the simultaneous equations. Here, n ₁ and n ₂ indicate complex refractive indexes unless otherwise specified.

  Therefore, as a method for obtaining the three-dimensional refractive index of the color filter without using the above Fresnel relational expression, there is a method based on a retardation value that can be directly measured, and this is applied to the red colored composition layer on the glass substrate. Describe the problems you will find if you do.

A transparent substrate 1 in FIG. 1 is formed with a non-alkali glass substrate having a thickness of 0.7 mm, which is generally used in a liquid crystal display device, and a thin colored film 2 is formed with red colored pixels of a color filter of the liquid crystal display device. A sample for measurement was prepared using the red coloring composition used for this purpose.
FIG. 2 shows a graph in which the spectral transmittance (T) of the red colored composition layer at this time is plotted on the vertical axis and the wavelength (λ) of light is plotted on the horizontal axis.

  The transparent substrate on which the red colored composition layer is formed is irradiated with polarized light having a wavelength of 400 nm to 780 nm from the direction of 45 ° and 90 ° to the sample surface using a spectroscopic ellipsometer (M-200 manufactured by JASCO). The retardation (Re) can be calculated from the obtained ellipso parameter Δ, and the measurement result of chromatic dispersion when Re is plotted on the vertical axis and the wavelength (λ) of light is plotted on the horizontal axis is shown in FIG.

  Here, when the light wavelength (λ) is plotted on the horizontal axis and the refractive index (n) is plotted on the vertical axis, the chromatic dispersion of the retardation of the substance is such that, if there is no anomalous dispersion, the magnitude of the inclination is closer to the shorter wavelength side. It is generally known that the curve is large. It is known that this property is derived from Cauchy's dispersion formula. Based on this, the chromatic dispersion of retardation (Figure 3) should also be a continuous (monotonically increasing or monotonically decreasing) curve at each wavelength. It is.

  As shown in FIG. 2, the red colored composition layer exhibits a flat transmittance of 80% or more from around 600 nm to around 700 nm. Therefore, in this wavelength region, the wavelength dispersion of retardation also changes monotonously according to the Cauchy dispersion formula. As expected, on the contrary, the wavelength dispersion of the retardation of FIG. 3 is a result of undulation from about 580 nm to about 700 nm.

  That is, due to the multiple interference that occurs between the transparent substrate and the thin film, the above-described waveform wavy phenomenon appears, indicating that the retardation has not been evaluated correctly. Therefore, when the three-dimensional refractive index is calculated based on such experimental results, the obtained three-dimensional refractive index includes many errors.

As another example, a transparent film made of triacetyl cellulose (hereinafter sometimes referred to as “TAC”) is used for the transparent substrate 1 of FIG. 1, and a polymerizable liquid crystal material having birefringence anisotropy is used for the thin film 2. The result of wavelength dispersion of retardation (Re) measured from the direction of incident angle of 45 degrees of the used sample is shown in FIG. In this case as well, ripples are seen in Re, and it can be confirmed that the influence of multiple interference generated between the transparent substrate and the thin film appears clearly.
JP 2007-279379 A JP-A-1-216235 Japanese Patent Laid-Open No. 2005-3386 SID Digest, 1094. (2000) Stone pots, Jpn. J. et al. Appl. Phys. 41, 4553 (2002) Fujiwara, “Spectroscopic Ellipsometry” Maruzen (2003) Wu et al., Jpn. J. et al. Appl. Phys. 39, 869 (2000)

  The three-dimensional refractive index and wavelength dependency of optical elements used in liquid crystal display devices such as optical compensation layers and color filters need to be evaluated in a thin film state of several μm in thickness. It is not appropriate to create, cut out and evaluate. Moreover, even if it is possible in principle, it is difficult in practice to measure the reflectance and transmittance of the multilayer thin film and calculate them using the Fresnel equation. For this reason, retardation measurement capable of highly accurate experimental measurement is performed, and a three-dimensional refractive index is derived from this data by some approximation.

  However, the retardation of a thin film formed on a transparent substrate is a wave that is affected by multiple interference in the thin film with respect to the incident angle or wavelength with respect to the thin film, as described above, in the conventional simple measurement method. Thus, there is a problem that the three-dimensional refractive index is incomplete for each wavelength or as basic data for calculating the wavelength dependence. In addition, in the conventional measurement method, analysis is performed only when the principal axis of the refractive index ellipsoid of the sample as shown in FIG. 7A described later coincides with Nx, Ny, and Nz in the reference coordinate system. Is the three-dimensional refractive index when the principal axes Nx ′, Ny ′, Nz ′ of the refractive index ellipsoid of the sample do not coincide with the laboratory coordinate system Nx, Ny, Nz, as shown in FIG. The means to find it was hardly studied.

  Therefore, the present invention provides a means for suppressing the retardation of the thin film from undulating with respect to a change in incident angle or wavelength, and then using this retardation, the principal axis of the refractive index ellipsoid of the thin film sample is in an arbitrary direction. An object of the present invention is to provide a means for calculating the three-dimensional refractive index with high accuracy, including the case where the angle is inclined. In particular, paying attention to the colored composition layer constituting the color filter as a thin film, first, the three-dimensional refractive index of the colored composition layer is accurately obtained, and then the thickness direction retardation Rth is precisely controlled using this value. Another object of the present invention is to provide a color filter substrate comprising a colored composition layer. If the accuracy of the three-dimensional refractive index value of the colored composition layer is low, the retardation of the entire optical element in the liquid crystal display device cannot be set to a desired value depending on the control of its thickness or the addition of a retardation adjusting agent. This is because the viewing angle characteristics are deteriorated due to attachment and light leakage.

The invention according to claim 1 for achieving the above object is as follows.
At least for the colored composition layer formed on the transparent substrate,
1. Obtaining linearly polarized light perpendicularly to obtain an in-plane optical axis of the colored composition layer ;
2. The includes an optical axis and the step of obtaining the linearly polarized light traveling in a plane perpendicular to the colored composition layer is incident on the colored composition layer in at least three or more of the plurality of incident angles .phi.i and retardation R (φi),
3. The retardation R (.phi.i) and formulas R of formula _{(2) (φi; n x} , n y, n z, β) with, as ρ of the formula (1) is as small as possible, three-dimensional In determining the three-dimensional refractive index of the colored composition layer by applying a three-dimensional refractive index measurement method having the steps of determining refractive indices _nx , _ny , _nz , and β, reflection from the colored composition layer a transparent substrate such as rate is as small as possible, the by performing measurement of retardation R (.phi.i), the three-dimensional refractive index n _x, step n _y, shall be specified for n _z,
4). Step you form a colored composition layer was controlled in the range of -20 to + 50 nm thickness direction retardation of the colored composition layer based on the value of the three-dimensional refractive index,
The color filter substrate manufacturing method is characterized by comprising:

（ここで、ｉは１から少なくとも３以上の範囲内の任意の整数、ｎ_x，ｎ_y，ｎ_zは薄膜の屈折率楕円体の直交する３成分、βは試料の屈折率楕円体おけるｘｙｚzの各軸方向に対
する傾斜角である。）

(Here, i definitive arbitrary _{integer, n x, n y, n} z is 3 orthogonal components of the refractive index ellipsoid of the thin film, beta is the refractive index ellipsoid of the sample in at least three or more ranges from 1 Xyzz The tilt angle with respect to each axis direction.)

（ここで、ｉ、ｎ_ｘ，ｎ_ｙ，ｎ_ｚは式（１）に同じ。また、式（２）は、θは偏光光の試料中における屈折角、ｄは試料の膜厚、βは試料の屈折率楕円体おけるｘｙｚの各軸方向に対する傾斜角である。）
着色組成物層からの反射率ができるだけ小さくなるような透明基板を用いてリタデーションを測定すると、測定に用いる入射偏光光が反射光として逆行する量が低減される結果、リタデーションが波打つ現象が抑止され正確なリタデーション値を得ることができる。
このリタデーション測定値とリタデーションの計算式Ｒ（φｉ；ｎ_ｘ，ｎ_ｙ，ｎ_ｚ，β）をフィティングさせることで計算式に含まれる着色組成物層の屈折率楕円体の固有値、すなわち３次元屈折率ｎ_ｘ，ｎ_ｙ，ｎ_ｚ、及び屈折率楕円体におけるｘｙｚの各軸方向に対する傾斜角βを精度良く定めることができる。また、この３次元屈折率を用い、着色組成物層の厚みを制御して厚み方向位相差Ｒｔｈを−２０〜＋５０ｎｍの範囲に設定すると色付、光漏れが生じない。但し、Ｒｔｈは、Ｒｔｈ＝｛（ｎ_ｘ＋ｎ_ｙ）／２−ｎ_ｚ｝×ｄで定義される数値であり、ｎ_ｘは着色画素層の平面内のｘ方向の屈折率を、ｎ_ｙは着色画素層の平面内のｙ方向の屈折率を、ｎ_ｚは着色画素層の厚み方向の屈折率を表す。ここで、ｎ_ｘはｎ_ｘ≧ｎ_ｙとする遅相軸、ｄは着色画素層の厚み（ｎｍ）である。
Ｒｔｈが−２０〜＋５０ｎｍの範囲外となる場合には、液晶表示装置に用いられる光学補償層や液晶材料など他の光学素子が有する複屈折性の波長分散性に適合しなくなり、斜めから見たときの黒表示において色付きや光漏れが生じ視認性が悪くなることや、カラーフィルタの着色画素層を形成するための感光性樹脂組成物の保存安定性が悪くなるといった問題を生じてしまう。

(Where i, _nx , _ny , and _nz are the same as in equation (1). Also, in equation (2), θ is the angle of refraction of the polarized light in the sample, d is the film thickness of the sample, and β is (An inclination angle with respect to each axis direction of xyz in the refractive index ellipsoid of the sample.)
When the retardation is measured using a transparent substrate in which the reflectance from the colored composition layer is as small as possible, the amount of incident polarized light used for the measurement as a reflected light is reduced, so that the phenomenon of retardation rippling is suppressed. An accurate retardation value can be obtained.
The retardation measurement formula for value and the retardation _{R (φi; n x, n} y, n z, β) the eigenvalues of the colored composition layer index ellipsoid included in the formula by which fitting, ie three-dimensional It is possible to accurately determine the refractive angles n _x , n _y , n _z , and the inclination angle β with respect to each axis direction of xyz in the refractive index ellipsoid. Further, when this three-dimensional refractive index is used to control the thickness of the colored composition layer and set the thickness direction retardation Rth in the range of -20 to +50 nm, coloring and light leakage do not occur. However, Rth is a numerical value defined by Rth = {(n _x + n _y ) / 2−n _z } × d, where _nx is a refractive index in the x direction in the plane of the colored pixel layer, and _ny is In the plane of the colored pixel layer, the refractive index in the y direction, and _nz represents the refractive index in the thickness direction of the colored pixel layer. Here, _{n x} is the slow axis of the _{n x} ≧ _{n y,} d is the thickness of the color pixel layer (nm).
When Rth is outside the range of -20 to +50 nm, the optical compensation layer used in the liquid crystal display device and other optical elements such as a liquid crystal material are not suitable for wavelength dispersion of birefringence, and viewed from an oblique direction. In such black display, coloring and light leakage may occur, resulting in poor visibility and storage stability of the photosensitive resin composition for forming the colored pixel layer of the color filter.

The invention according to claim 2
A step of obtaining the retardation R of claim 1, wherein (.phi.i), for the same the colored composition layer formed on a transparent substrate of a different k pieces refractive index (k ≧ 2), successively retardation R _k ( φi), and for each φi, out of the k retardations R _k (φi), a retardation R _k (φi) corresponding to the transparent substrate having the minimum reflectance at φi is _{obtained as} R (φi The method for producing a color filter substrate according to claim 1, wherein:

  Prepare a plurality of transparent substrates having different refractive indexes, and have the lowest reflectance (highest transmittance) among the measured values of retardation R (φi) for each φi of the colored composition layer formed on the substrate. The retardation R (φi) value corresponding to the transparent substrate is adopted as a highly reliable numerical value with less influence of multiple interference. The number k of transparent substrates is preferably about 4,5.

In the invention according to claim 3, when the refractive index of the transparent substrate is n ₂ and the refractive index of the colored composition layer formed on the transparent substrate is n ₁ , | n ₂ −n ₁ | ≦ 0.1 The method for producing a color filter substrate according to claim 1, wherein a transparent substrate satisfying the above is used.
It is a thing.

  If the refractive index difference between the transparent substrate and the colored composition layer is set within such a range, the effect of suppressing the phenomenon of retardation undulating becomes extremely remarkable. As a result, a more accurate value of retardation is obtained.

  If the three-dimensional refractive index of the colored composition layer is known, the retardation value can be freely set by using a retardation adjusting agent. Therefore, such a liquid crystal display device can include a color filter having a desired retardation. The retardation adjusting agent will be described later.

 According to the present invention, a transparent substrate to be combined with a colored composition layer constituting a color filter is selected from those having as little reflectivity as possible from the colored composition layer, thereby preventing retardation of the retardation. A measured value is obtained. Next, a highly accurate calculation of the three-dimensional refractive index of the colored composition layer on the transparent substrate is achieved by making a suitable calculation formula for calculating the three-dimensional refractive index of the colored composition layer from the accurate retardation value. Is possible. Next, by adding a retardation adjusting agent to the colored composition layer to change the birefringence of the colored pixels constituting the color filter, the possibility of precisely controlling Rth is opened. If a color filter substrate having colored pixels whose Rth is precisely controlled is manufactured and used, a liquid crystal display device of good quality with little viewing angle dependency can be manufactured.

  In the following, embodiments of the present invention will be described in the order of the apparatus surface, the refractive index calculation method, the basic principle of the present invention, and finally the examples.

The three-dimensional refractive index measurement apparatus includes means for obtaining linearly polarized light perpendicularly to a sample on which a thin film of at least one layer is formed on a transparent substrate and obtaining an in-plane optical axis of the thin film, the optical axis And a polarized light traveling in a plane perpendicular to the thin film is incident on the thin film at at least one or more incident angles φi to cause retardation R (φi) (hereinafter also referred to as a phase difference for simplicity) means for determining the three-dimensional refractive formula for rate _{R (φi; n x, n} y, n z, β) means for determining the further the retardation R (.phi.i) and formulas R (φi; n _x, n _y , _nz , β)

ができるだけ小さくなるように、ｎ_x，ｎ_y，ｎ_z，βを求める手段、とを少なくとも具備した３次元屈折率測定装置である。すなわち、垂直入射及び斜入射におけるリタデーション測定結果に、式（１）より算出されるリタデーションの計算値をカーブフィッティングさせて誤差ρの最小値を求めることで、透明基板と薄膜との間で生じる多重干渉の影響を平均化することができる測定装置である。

So they become as small as possible, which is _{n x, n y, n z} , means for obtaining the beta, city three-dimensional refractive index measuring device at least comprises a. That is, by multiplying the retardation measurement result obtained by the equation (1) with the retardation measurement result at normal incidence and oblique incidence to obtain the minimum value of the error ρ, the multiple generated between the transparent substrate and the thin film is obtained. It is a measuring device that can average the influence of interference.

Furthermore, the three-dimensional refractive index measurement apparatus includes at least two or more transparent substrates having different refractive indexes on which thin films having the same layer configuration are formed. Equation (1) can be applied to the thin film on the transparent substrate as much as possible. Means for obtaining n _x , n _y , n _z , and β are provided so as to be smaller, and n _x , n _y , n _z , and β are three-dimensionally refracted on the transparent substrate where Equation (1) is minimized. And means for determining the rate. That is, when the refractive index of the transparent substrate is n ₂ and the refractive index of the thin film formed in the first layer on the transparent substrate is n ₁ , at least two or more different | n ₂ −n ₁ | samples can be equipped with a, preferably capable of continuous measurement with automatic, n _x in the transparent substrate, each of the formula (1) is minimized, n _y, n _z, means for determining the three-dimensional refractive indexes of the β including.

  Specifically, as shown in FIG. 5, the light source unit 5, the spectroscope 6, the polarizer 7, the sample stage 8, the analyzer 9, the detection unit 10, the data processing device 11, and the display device 12 are configured as basic units. It is a device. As the light source part 5, what has a broad wavelength distribution within a measurement wavelength range, for example, a white light source, can be used. The spectroscope 6 is a unit that projects a measurement light beam onto the surface of the object to be measured, a collimator optical system (lens, concave mirror, etc.) that forms a parallel light beam with a uniform cross-sectional intensity distribution, and a wavelength for extracting a single color of a specific wavelength. Selection means such as a narrow band filter may be included. The polarizer 7 is a polarizer for extracting linearly polarized light having a specific polarization direction. The polarizing element of the analyzer 9 is configured to have a predetermined polarization direction relationship with the corresponding polarizing element, for example, parallel Nicols. The detection unit 10 is a light detection element that generates an electrical signal corresponding to the light intensity, and is configured by, for example, a photodiode or a two-dimensional CCD element (charge coupled device), and can be configured to arbitrarily sample the detection output. ing. Moreover, the apparatus etc. which perform amplification and A / D conversion part of the obtained light beam can be included. The data processing device 11 is a computer that performs data processing of detection signals, operation control of the device, and the like. Further, the spectroscope 6 serving as a wavelength selection unit may be provided before the detector of the light receiving unit or between the polarizer 7 and the analyzer 9 instead of being provided between the light source unit 5 and the polarizer 7. Here, the light source may be monochromatic light such as a laser. In this case, both monochromaticity and linear polarization may have a certain width.

The sample (measurement) stage 8 allows the sample attached to the sample stage to be rotated about a normal incident light axis and a rotation axis perpendicular to the light axis. The sample stage 8 is configured to be driven by a power source under the control of an unillustrated rotating stage that can be rotated by a shaft, a stepping motor, etc., an encoder that generates a rotation angle position signal of the rotating stage, and a drive control unit. ing. Also on the sample stage 8, when n ₂ the refractive index of the transparent substrate, the refractive index of the thin film formed on a first layer on the transparent substrate and _{n 1, | n 2 -n 1} | different at least Multiple stages of three or more samples can be mounted and the stage can be replaced by a stepping motor, etc., an encoder that generates a stage position signal, and a drive control unit so that automatic continuous measurement is possible Is provided with a configuration driven by a power source.

  With this configuration, it is possible to obtain the optical axis in the plane of the sample, that is, the main refractive index direction by allowing substantially linearly polarized light to enter the sample perpendicularly. Further, the sample stage can be rotated around the vertical incident optical axis so that the optical axis direction is included in the oblique incident surface, and the oblique incident incident surface can be rotated around the rotational axis perpendicular to the light axis. Retardation can be obtained by obliquely incident polarized light on the sample from at least one or more oblique incidence angles in a plane including the axis and perpendicular to the sample. In this state, transmitted light by normal incidence measurement and oblique incidence measurement is detected in parallel, and birefringence characteristics (main refractive index direction, retardation value, etc.) are obtained respectively, and the three-dimensional refractive index is combined with the normal incidence measurement results. Is the basic data to be calculated.

  An example in which the retardation (Re) obtained by this apparatus is plotted on the vertical axis and the incident angle is plotted on the horizontal axis is shown in FIG.

  In the conventional measuring apparatus, the analysis is performed only when the principal axis of the refractive index ellipsoid of the sample as shown in FIG. 7A coincides with Nx, Ny, Nz in the reference coordinate system. The means for obtaining the three-dimensional refractive index when the principal axes Nx ′, Ny ′, Nz ′ of the refractive index ellipsoid of the sample as shown in (b) do not coincide with the laboratory coordinate system Nx, Ny, Nz are almost studied. It wasn't.

  Whether or not the refractive index ellipsoid of the sample is tilted from the reference coordinate system as shown in FIG. 7B can be determined by being left-right asymmetric as shown by □ (measured value) in FIG. it can.

Then 3-dimensional refractive indices n _x by measured values and curve fitting of the retardation, n _y, the calculation formula for obtaining the n _z will be described. Here, the present inventors can calculate the tilt angle of the optical axis in the retardation calculation formula corresponding to FIG. 7B when the refractive index ellipsoid is tilted by β degrees from the z-axis direction. It has been found that it is preferable to use equation (2). (For example, refer nonpatent literature 4).

但し、ｎ_ｘ，ｎ_ｙ，ｎ_ｚはそれぞれ基準座標系におけるｘ軸方向、ｙ軸方向、ｚ軸方向の３次元屈折率を表し面内にｎ_ｘ，ｎ_ｙ（ｎ_ｘ≧ｎ_ｙ）、厚さ方向にｎ_ｚとする。また、入射角をφｉ、試料の膜厚をｄ、偏光光の試料中における屈折角をθとする。
上式でβ＝０とすれば図７（ａ）の屈折率楕円体の主軸方向が基準座標と平行な場合に対応する。ここで、θとβだけがリタデーションを測定するための斜入射（垂直入射も含む）の角度φｉの関数であることに注意する。
入射角φｉは、垂直入射時の略直線偏光の偏光光を試料に垂直入射させて求められる試料の面内の光学軸、すなわち主屈折率方向を含む面内の角もしくは該主屈折率方向に直交する面内の角であり、測定開始時にいずれかを選択して測定もしくは両方連続して測定することができる。βは、入射角として主屈折率方向を含む面内の角として測定を行った場
合はｘ軸に対する傾斜角を、入射角として該主屈折率方向に直交する面内の角として測定を行った場合にはｙ軸に対する傾斜角として取り扱われるため、両方の角度で測定してｘ軸およびｙ軸の２軸に対する傾斜角を求めてもよい。

_{However, n x, n y, n} z x -axis direction in the respective reference coordinate system, y-axis direction, the z-axis direction of the three-dimensional refractive index represents plane _{n x, n y (n x} ≧ n y), It is set to _{nz in the} thickness direction. Also, the incident angle is φi, the film thickness of the sample is d, and the refraction angle of the polarized light in the sample is θ.
If β = 0 in the above equation, this corresponds to the case where the principal axis direction of the refractive index ellipsoid in FIG. 7A is parallel to the reference coordinates. Note that only θ and β are functions of the angle φi of oblique incidence (including normal incidence) for measuring retardation.
The incident angle φi is an optical axis within the surface of the sample obtained by vertically incident polarized light of substantially linear polarized light at the time of normal incidence, that is, an in-plane angle including the main refractive index direction or the main refractive index direction. It is an angle within the orthogonal plane, and either one can be selected at the start of measurement, or both can be measured continuously. When β was measured as an in-plane angle including the main refractive index direction as an incident angle, an inclination angle with respect to the x-axis was measured as an incident angle and an in-plane angle perpendicular to the main refractive index direction. In some cases, it is handled as an inclination angle with respect to the y-axis, and therefore, the inclination angle with respect to the two axes of the x-axis and the y-axis may be obtained by measuring at both angles.

Equation (2) Further, since the該屈much trouble theta considered to indicate different values the incident surface outwardly as the incident plane direction, respectively theta _1, when the theta _2, represented by the following formula (4) Thus, the three-dimensional refractive index can be obtained with higher accuracy.

但し、
θ₁は式（５）、θ₂は式（６）で表される屈折角であり、入射角をφ、偏光光の試料中における屈折角をθ、試料の屈折率楕円体のｚ軸方向からの傾斜角をβ、ｎ'を式（７）で表される入射面内の屈折率とする。

However,
θ ₁ is the refraction angle represented by Equation (5), θ ₂ is the refraction angle represented by Equation (6), the incident angle is φ, the refraction angle of the polarized light in the sample is θ, and the z-axis direction of the refractive index ellipsoid of the sample The inclination angle from the angle β is β, and n ′ is the refractive index in the incident surface represented by the equation (7).

式（２）にｎ_x, ｎ_y, ｎ_zおよびβを逐次的に当てはめてリタデーションを算出し、実測によって得られた全ての入射角での測定結果との誤差が最小になるように、当てはめるｎ_x, ｎ_y, ｎ_z、およびβの数値をフィッティングすることで３次元屈折率およびｚ軸方向からの傾斜角βを決定する。このカーブフィッティングのアルゴリズムとしては、シンプレックス法などの線形計画法、Ｌｅｖｅｎｂｕｒｇ−Ｍａｒｑｕａｒｄｔ法などの非線形カーブフィッティング法などが好適に用いられる。また、βとしてｚ軸からの傾斜だけでなくｘ、ｙ軸からの傾斜角があっても構わないし、上述したように、０であっても構わない。

The n _x formula (2), to calculate the retardation n _y, by applying the n _z and β sequentially, so that the error between the measurement result at all angles of incidence obtained by actual measurement is minimal, fitting n _x, n _y, to determine the n _z, and the inclination angle from the three-dimensional refractive index and the z-axis direction numerically fitting the the beta beta. As the curve fitting algorithm, a linear programming method such as a simplex method, a non-linear curve fitting method such as a Levenburg-Marquardt method, or the like is preferably used. Further, β may include not only the inclination from the z axis but also the inclination angle from the x and y axes, and may be 0 as described above.

The above, n _x, n _y, if n _z and β is Motomare, n _x by the following equation _{(8) ', n y'} , n z ' is obtained.

しかしながら、図８に示すような多重干渉による影響を受けたリタデーションの入射角依存性がある測定結果に、上記のアルゴリズムを適用して屈折率を算出しても、信頼性に欠けることが明らかであり、また収束性が悪い場合もあった。

However, it is clear that even if the refractive index is calculated by applying the above algorithm to the measurement result having the incidence angle dependency of the retardation influenced by the multiple interference as shown in FIG. There were also cases where convergence was poor.

Thus, as a result of intensive studies in view of the above circumstances, the present inventors have determined that the refractive index of the transparent substrate is n ₂ and the refractive index of the thin film formed in the first layer on the transparent substrate is n ₁ . By selecting a transparent substrate so that | n ₂ −n ₁ | becomes as small as possible in a certain wavelength, preferably in a considerable wavelength range, preferably | n ₂ −n ₁ | ≦ 0.1. It has been found that a highly reliable retardation value can be obtained, resulting in a highly accurate three-dimensional refractive index value.
That is, it has been found that the influence of optical multiple interference can be minimized by selecting the material of the transparent substrate so as to minimize the difference in refractive index between the transparent substrate and the thin film. It is generally known that optical interference greatly depends on the intensity of reflected light between the substrate and the thin film, and the intensity R of the reflected light determines the refractive index of each layer as n ₂ and n _1. Is given by the following equation (9).

透明基板と薄膜の屈折率差が小さくなれば反射光の強度が弱くなり、リタデーション測定に資する透過光として透過していく量が増大するため、光学干渉による影響を最小化できる。透明基板の屈折率ｎ₂の波長依存性は予め測定できるので、値の異なるものを複数準備し、これに薄膜を形成しておくのが好ましい。波長により透明基板と薄膜の屈折率が変動する場合には、波長ごとに反射率ができるだけ小さくなるように透明基板を切り替えてリタデーションを測定して一群の基礎データとするのが望ましい。

If the difference in refractive index between the transparent substrate and the thin film becomes small, the intensity of reflected light becomes weak and the amount of transmitted light that contributes to retardation measurement increases, so that the influence of optical interference can be minimized. Since the wavelength dependence of the refractive index n ₂ of the transparent substrate can be measured in advance, it is preferable to prepare a plurality of different values and to form a thin film thereon. When the refractive index of the transparent substrate and the thin film varies depending on the wavelength, it is desirable to switch the transparent substrate so that the reflectance becomes as small as possible for each wavelength, and measure the retardation to obtain a group of basic data.

Here, it should be noted that a low reflectance from the thin film surface means a high transmittance from the transparent substrate. When the thin film on the transparent substrate has two or more layers, n ₂ can be considered as an average refractive index of some kind of them.

Further, in the present invention, the step of obtaining the above-mentioned retardation, curve-fitting the calculated value of the retardation to the measurement result at the normal incidence and the measurement result at the oblique incidence, and the minimum value of the error ρ calculated from the equation (1) When the refractive index of the transparent substrate is n ₂ and the refractive index of the thin film formed as the first layer on the transparent substrate is n ₁ , at least three different | n ₂ −n ₁ | A plurality of samples can be mounted, automatic continuous measurement is possible, and the step of calculating the minimum value of | n ₂ −n ₁ | by curve fitting the error ρ in each sample is included. The three-dimensional refractive index can be obtained more efficiently.

  Actually, as shown in FIG. 9, when the refractive index of the transparent substrate is increased from 1.52 to 1.69, 1.77, it becomes clear that the undulation phenomenon disappears with respect to the incident angle. It was. Therefore, it is clear that if the fitting is performed such that the error ρ between the retardation value and the calculated value is minimized, the birefringence value of the thin film with high accuracy can be obtained. Furthermore, since the refractive index of the transparent substrate when the error ρ is the smallest becomes substantially equal to the refractive index of the thin film, it is possible to easily obtain the refractive index simultaneously with the birefringence. It is possible to omit the complicated steps required for obtaining the rate and the birefringence.

  A sample that can be measured by the three-dimensional refractive index measuring apparatus of the present invention will be described below. In addition to the above-described optical element, at least one thin film is formed on the transparent substrate unless departing from the spirit of the present invention. Any sample may be used as long as it is formed.

  Transparent substrates include glass plates such as soda lime glass, low alkali borosilicate glass and non-alkali aluminoborosilicate glass, resin plates such as polycarbonate, polymethyl methacrylate, and polyethylene terephthalate, triacetyl cellulose (hereinafter “TAC”). A transparent film made of Moreover, as a transparent base material for eliminating the refractive index difference from the thin film, synthetic glass, borofloat, BK7, K5, B270, Zerodur, SK11, BaK4, SSKN8, F2, which are optical glass manufactured by Shot Japan Co., Ltd., BaSF1, SF2, LaKN22, SF8, SF18, SF10, SF14, Sapphire, SF11, SFL11, LaSFN30, SFL6, SF6, SF57, LaSFN9, CORNING Pyrex (registered trademark) 7740, C0550, HOYA B13 BaFN10, SF5, FD5, FD10, TAC4, OHARA S-TIH1, 3, 4, 6, 10, 11, 13, 14, 18, 23, 53, 53, L-TIH53, S-NPH1, S -NPH2, 53, -NBH5, 8, 51, 52, 53, 55, L-NBH54, S-LAH51, 52, 53, 55, 58, 59, 60, 63, 64, 65, 66, 71, 79, L-LAH53, 81 83, 84, 85, S-LAM2, 3, 7, 51, 52, 54, 55, 58, 59, 60, 61, 66, L-LAM 60, 69, 72, S-BAH10, 11, 27, 28 32, S-TIM1, 2, 3, 5, 8, 22, 25, 27, 28, 35, 39, S-FTM16, L-TIM28, S-BAM3, 4, 12, S-NBM51, S-TIL1 2, 6, 25, 26, 27, S-YGH51, S-LAL7, 8, 9, 10, 12, 13, 14, 18, 54, 56, 58, 59, 61, L-LAL12, 13, S -BSM2, 4, 9, 10, 14, 15 16, 18, 22, 25, 28, 71, 81, S-PHM52, 53, S-BAL2, 3, 11, 12, 14, 35, 41, 42, L-PHL1, 2, L-BAL35, 42, Optical glass such as S-NSL3, 5, 36, S-BSL7, L-BSL7, S-FSL5, S-FPL51, and S-FPL53 can be preferably used.

  As the thin film layer, in addition to the colored composition layer constituting the color filter, a polymerizable liquid crystal material having birefringence anisotropy for optically compensating the birefringence of the liquid crystal display device, and indium oxide for driving the liquid crystal And a transparent electrode made of a combination of metal oxides such as tin oxide, zinc oxide and antimony oxide.

  In this case, when the substrate to be measured is a color filter, the retardation value of the single colored pixel layer is measured by using a mask processed so as to transmit only the single colored pixel layer of R, G, and B. Can be requested. Further, for example, when light having a wavelength of 610 nm is used as incident light, the phase difference value caused only by the red colored pixel, in the case of 550 nm, the phase difference value caused only by the green colored pixel, in the case of 450 nm, The approximate value of the single colored pixel layer can be estimated as the phase difference value caused only by the blue colored pixels. In addition, when the board | substrate to measure is a single colored pixel layer (the structure which formed the coating film of the monochrome color filter coloring composition in the transparent substrate) in any one of R, G, and B, without passing through a mask The phase difference can be measured.

  In the three-dimensional refractive index measurement method of the present invention, a general-purpose measuring device with high measurement accuracy is used as a measuring device for obtaining retardation, and the three-dimensional refractive index is separately calculated from the obtained retardation and calculation formula. Good. Suitable measuring devices include a birefringence measuring device that measures the anisotropy, optical constant, etc. of the sample by detecting the polarization state when light is transmitted through the sample or reflected from the surface thereof, or photoelastic modulation. An apparatus called transmission-type polarimetry by the method is preferable, and a Mueller matrix polarimeter is more preferably used.

Next, the color filter according to the present invention will be described.
FIG. 12 is a schematic cross-sectional view of a color filter according to an embodiment of the present invention.
First, a method for forming a colored composition layer constituting a color filter will be described. On the substrate surface on which the colored composition layer is provided, a counter substrate carrying layer for making the cell gap of a liquid crystal display device uniform, There may be a cell gap control raising layer and a retardation layer, and the same forming method can be applied to these.

On a substrate 13 shown in FIG. 12, a black matrix 14 formed by patterning a metal such as chromium or a photosensitive black resin composition is formed by a conventional method. As the substrate 13 to be used, a transparent substrate is suitable, and specifically, a glass plate, a resin substrate such as polycarbonate, polymethyl methacrylate, polyethylene phthalate or the like is suitably used. In addition, a transparent electrode made of a combination of metal oxides such as indium oxide, tin oxide, zinc oxide and antimony oxide is formed on the surface of the glass plate or resin plate for driving the liquid crystal after the liquid crystal panel is formed. Also good.
First, the photosensitive composition containing the thermosetting resin according to one embodiment of the present invention is uniformly applied on the substrate 13 by spray coating, spin coating, roll coating, slit coating, or the like. ,dry. The layer formed in this step is referred to as “photosensitive composition layer”. Next, the formed photosensitive composition layer is patterned by photolithography. That is, exposure is performed by irradiating active energy rays such as ultraviolet rays and electron beams through a photomask having a desired light-shielding pattern, and then development is performed using a developer such as an organic solvent or an alkaline aqueous solution. Here, in the exposure step, the portion of the photopolymerizable monomer irradiated with the active energy ray is polymerized and cured. Further, when a photosensitive resin is contained, the resin is also crosslinked and cured. In order to improve the exposure sensitivity, after forming the photosensitive composition layer, a solution of a water-soluble or alkaline water-soluble resin (for example, polyvinyl alcohol or water-soluble acrylic resin) is applied and dried, so that oxygen Exposure may be performed after forming a film that suppresses polymerization inhibition due to.

Next, in the development step, a desired pattern is formed by washing away the portion that has not been irradiated with the active energy ray with a developer. As a development processing method, a shower development method, a spray development method, a dip (immersion) development method, a paddle (liquid accumulation) development method, or the like can be applied. As the developer, an alkaline developer such as an aqueous solution such as sodium carbonate or caustic soda, or an organic alkali solution such as dimethylbenzylamine or triethanolamine is mainly used. Moreover, as a developing solution, what added the antifoamer and surfactant was used as needed.
Finally, it is baked and the same operation is repeated for other colors to produce a color filter. That is, a colored composition layer including red colored pixels 15R, green colored pixels 15G, and blue colored pixels 15B is formed on the substrate 13 on which the black matrix 14 is formed. Furthermore, the counter substrate carrying layer 16 for making the cell gap of the liquid crystal display device uniform can be formed on these colored pixels.

  FIG. 13 shows a cell gap control raising layer 17 and a retardation layer 18 on the substrate surface provided with the colored composition layer, and a counter substrate for making the cell gap of the liquid crystal display device uniform. The structure in which the support layer 16 was formed was illustrated.

It is widely used that the colored pixel layer contains a pigment for coloring. For example, C.I. I. Pigment Red 7, 14, 41, 48: 2, 48: 3, 48: 4, 81: 1, 81: 2, 81: 3, 81: 4, 146, 168, 177, 178, 179, 184, 185, Red pigments such as 187, 200, 202, 208, 210, 246, 254, 255, 264, 270, 272, and 279 can be used, and a yellow pigment and an orange pigment can also be used in combination.
Examples of yellow pigments include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 24, 31, 32, 34, 35, 35: 1, 36, 36: 1, 37, 37: 1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 126, 127, 128, 129, 147, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 179, 180, 181, 182, 187 188,193,194,199,198,213,214, and the like.
Examples of the orange pigment include C.I. I. Pigment Orange 36, 43, 51, 55, 59, 61, 71, 73 and the like.

In the case where the red colored pixel layer contains one or more of diketopyrrolopyrrole red pigment and anthraquinone red pigment among these pigments, it is preferable because any thickness direction retardation can be easily obtained.
This is because the diketopyrrolopyrrole red pigment can be made positive or negative and the absolute value thereof can be controlled to some extent by devising the finer treatment, and the anthraquinone red pigment is This is because it is easy to obtain Rth close to 0 regardless of the miniaturization process.
The amount used is 10 to 90% by weight of the diketopyrrolopyrrole red pigment and 5 to 70% by weight of the anthraquinone red pigment based on the total weight of the pigment. From the viewpoint of contrast and the like, in particular, when focusing on the contrast, it is more preferable that the diketopyrrolopyrrole red pigment is 25 to 75% by weight and the anthraquinone red pigment is 30 to 60% by weight.

The red colored pixel layer can contain a yellow pigment or an orange pigment for the purpose of adjusting the hue, but it is preferable to use an azo metal complex-based yellow pigment from the viewpoint of increasing the contrast.
The amount used is preferably 5 to 25% by weight based on the total weight of the pigment, and if it is less than 5% by weight, hue adjustment such as sufficient brightness improvement cannot be achieved, and the amount exceeds 30% by weight. In this case, since the hue is shifted too yellow, the color reproducibility is deteriorated.

In the above, examples of the diketopyrrolopyrrole red pigment include C.I. I. Pigment Red 254, an anthraquinone red pigment, "C.I. I. Pigment Red
177, examples of the azo metal complex yellow pigment include C.I. I. Pigment Yellow 150 is preferable in terms of excellent light resistance, heat resistance, transparency, coloring power, and the like.

For the green colored pixel layer, for example, C.I. I. Green pigments such as Pigment Green 7, 10, 36, 37, and 58 can be used, and a yellow pigment can be used in combination.
As the yellow pigment, the same pigments as those mentioned for the red pixel can be used.

  The green pixel layer contains at least one of a halogenated metal phthalocyanine green pigment, an azo yellow pigment, and a quinophthalone yellow pigment among these pigments, because it is easy to obtain an arbitrary Rth. preferable. This is because the halogenated metal phthalocyanine green pigment can control the thickness direction retardation to some extent by selecting the central metal, and the azo yellow pigment has a positive thickness direction retardation regardless of the miniaturization treatment. This is because the quinophthalone-based yellow pigment can obtain a negative thickness direction retardation regardless of the refining treatment.

The amount used is 30 to 90% by weight of the halogenated metal phthalocyanine green pigment, 5 to 60% by weight of the azo yellow pigment, and 5 to 60% by weight of the quinophthalone yellow pigment based on the total weight of the pigment. This is preferable from the viewpoint of the hue, brightness, and film thickness of the pixel.
More preferably, the halogenated metal phthalocyanine green pigment is 50 to 85% by weight, the azo yellow pigment is 5 to 45% by weight, and the quinophthalone yellow pigment is 5 to 45% by weight.

  In the above, examples of the halogenated metal phthalocyanine green pigment include C.I. I. Pigment Green 7, 36, and zinc halide phthalocyanine pigments and azo yellow pigments include C.I. I. Pigment Yellow 150 and quinophthalone yellow pigments include C.I. I. Pigment Yellow 138 is preferable in terms of excellent light resistance, heat resistance, transparency, coloring power, and the like.

For the blue pixel layer, for example, C.I. I. Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64, and the like can be used, and a purple pigment can be used in combination. Examples of purple pigments include C.I. I. Pigment
Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, 50 etc. are mentioned.

  When the blue pixel layer contains one or more of a metal phthalocyanine blue pigment and a dioxazine violet pigment among these pigments, it is easy to obtain a thickness direction retardation close to 0 from negative. The amount used is 40 to 100% by weight of the metal phthalocyanine blue pigment and 1 to 50% by weight of the dioxazine violet pigment based on the total weight of the pigment. It is preferable from a point, Furthermore, it is more preferable to make a metal phthalocyanine blue pigment 50 to 98 weight% and a dioxazine purple pigment 2 to 25 weight%.

  In the above, examples of the metal phthalocyanine blue pigment include C.I. I. Pigment Blue 15: 6, and dioxazine-based purple pigments include C.I. I. Pigment Violet 23 is preferable in terms of excellent light resistance, heat resistance, transparency, coloring power, and the like.

Moreover, the retardation regulator mentioned above can be added to the coloring composition of 1 or more colors to the color filter of this invention. Retardation adjustment is an additive that can adjust the thickness direction retardation of a color filter formed as a colored coating film on a transparent substrate, a reflective substrate, or a semiconductor substrate using a colored composition.
The compound used is preferably an organic compound with good dispersibility in order to ensure a high contrast of 1000 or 3000 or more.
In addition, when a multi-color filter is formed on a transparent substrate or the like, it may be added to all colors, but it can be added to only one or two colors.

  Specifically, an organic compound having a planar structure group having one or more crosslinkable groups, a melamine resin, a porphyrin compound polymerizable liquid crystal compound, and styrene are reacted with a non-aromatic polyvalent carboxylic acid-containing monomer. What is necessary is just to select 1 or more types selected from the polymerization composition which becomes.

Usually, it is considered that the retardation in the thickness direction of the entire film can be canceled only by adding particles having a planar structure group having birefringence opposite to that of pigment or other resin.
However, simply adding particles having a planar structure group will cause the particles themselves to be randomly oriented, and the influence on the thickness direction retardation of the entire film will be small.
As a result of intensive investigations, the present inventors have found that by providing at least one crosslinkable group of the planar structure group, the thickness direction retardation of the entire film is greatly changed and exhibits a sufficient effect. It was. That is, for example, by having a functional group that crosslinks in the photo-curing process or photo-curing process in the photolithography process, the planar structural group does not rotate freely, and the planar structural group is more susceptible to shrinkage during thermal curing. By being easily oriented and fixed in the same direction, the function of phase difference control can be effectively expressed.

  As the planar structural group, it has at least one aromatic ring, and in the case of monocyclic hydrocarbon, phenyl group, cumenyl group, mesityl group, tolyl group, xylyl group, benzyl group, phenethyl group, styryl group, For polycyclic hydrocarbons such as cinnamyl and trityl groups, pentarenyl, indenyl, naphthyl, biphenylene, acenaphthylene, fluorene, phenanthryl, anthracene, triphenylene, pyrene, naphthacene, pentaphen, pentacene Known compounds such as a group, a tetraphenylene group, and a trinaphthylene group can be used. For heteromonocyclic compounds, pyrrolyl group, imidazolyl group, pyrazolyl group, pyridyl group, pyrazinyl group, triazine group, etc.For heteropolycyclic compounds, indolizinyl group, isoindolyl group, indolyl group, purinyl group, quinolyl group, isoquinolyl group, phthalazinyl Groups, naphthyridinyl groups, quinoxalinyl groups, cinolinyl groups, carbazolyl groups, carbolinyl groups, acridinyl groups, porphyrin groups, and the like, which have substituents such as hydrocarbon groups and halogen groups. Also good.

  The at least one crosslinkable group attached to the planar structure group includes an unsaturated polymerizable group such as a vinyl group or an ethynyl group or a functional group such as an amino group, a mercapto group, a hydroxyl group, an aldehyde group, an isocyanate group, or a thioisocyanate group. It is preferably a thermally polymerizable group such as a group, an epoxy group or a glycidyl group.

  As the melamine compound, a commercially available compound represented by the following general formula (10) can be preferably used, but any compound having the above-described planar structure group may be used, and a known compound can be used. Examples of melamine compounds are given below.

式中、Ｒ1、Ｒ２、Ｒ３ はそれぞれ水素原子、メチロール基、アルコキシメチル基、アルコキシｎ−ブチル基、Ｒ４、Ｒ５、Ｒ６ はそれぞれメチロール基、アルコキシメチル基、アルコキシｎ−ブチル基である。二種類以上の繰り返し単位を組み合わせたコポリマーを用いてもよい。二種類以上のホモポリマーまたはコポリマーを併用してもよい。

In the formula, R1, R2, and R3 are a hydrogen atom, a methylol group, an alkoxymethyl group, an alkoxy n-butyl group, and R4, R5, and R6 are a methylol group, an alkoxymethyl group, and an alkoxy n-butyl group, respectively. A copolymer combining two or more kinds of repeating units may be used. Two or more homopolymers or copolymers may be used in combination.

  Alternatively, a compound having a porphyrin skeleton represented by the following general formula (11) can be preferably used. n is an integer of 1 to 20, and 2 is preferably used.

式中、Ｒ15〜Ｒ22はそれぞれ独立に水素原子、ハロゲン原子、アルコキシ基、アルキルチオ基、置換もしくは未置換のフェノキシ基、置換もしくは未置換のナフトキシ基、置換もしくは未置換のフェニルチオ基、または置換もしくは未置換のナフチルチオ基を表す。

In the formula, R15 to R22 are each independently a hydrogen atom, a halogen atom, an alkoxy group, an alkylthio group, a substituted or unsubstituted phenoxy group, a substituted or unsubstituted naphthoxy group, a substituted or unsubstituted phenylthio group, or a substituted or unsubstituted group. Represents a substituted naphthylthio group.

Specific examples of the porphyrin compound represented by the general formula (11) used in the present invention are described below. Examples of the halogen atom in R15 to R22 include fluorine, chlorine, bromine and iodine.
The alkoxy group and thioalkyl group are not particularly limited, but the alkyl group in the substituent is preferably a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, and having 1 to 8 carbon atoms. A linear, branched or cyclic alkyl group is particularly preferred. Z represents -CH2-, -N-.

  Specific examples of the alkyl group in the alkoxy group and thioalkyl group include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, t-butyl group. Group, n-pentyl group, iso-pentyl group, 2-methylbutyl group, 1-methylbutyl group, neo-pentyl group, 1,2-dimethylpropyl group, 1,1 dimethylpropyl group, cyclopentyl group, n-hexyl group, 4-methylpentyl group, 3methylpentyl group, 2-methylpentyl group, 1-methylpentyl group, 3,3-dimethylbutyl group, 2,3-dimethylbutyl group, 1,3-dimethylbutyl group, 2,2 -Dimethylbutyl group, 1,2-dimethylbutyl group, 1,1-dimethylbutyl group, 3-ethylbutyl group, 2-ethylbutyl group, 1-ethylbutyl Group, 1,2,2-trimethylbutyl group, 1,1,2-trimethylbutyl group, 1-ethyl-2-methylpropyl group, cyclohexyl group, n-heptyl group, 2-methylhexyl group, 3-methylhexyl Group, 4-methylhexyl group, 5 methylhexyl group, 2,4-dimethylpentyl group, n-octyl group, 2-ethylhexyl group, 2,5-dimethylhexyl group, 2,5,5-trimethylpentyl group, 2 , 4-dimethylhexyl group, 2,2,4-trimethylpentyl group, n-octyl group, 3,5,5-trimethylhexyl group, n-nonyl group, n-decyl group, 4-ethyloctyl group, 4- Ethyl 4,5-dimethylhexyl group, n-undecyl group, n-dodecyl group, 1,3,5,7-tetraethyloctyl group, 4-butyloctyl group, 6,6-diethyloctyl group Til, n-tridecyl, 6-methyl-4-butyloctyl, n-tetradecyl, n-pentadecyl, 3,5-dimethylheptyl, 2,6-dimethylheptyl, 2,4-dimethylheptyl Group, 2,2,5,5-tetramethylhexyl group, 1-cyclopentyl-2,2-dimethylpropyl group, 1-cyclohexyl-2,2-dimethylpropyl group and the like.

  Specific examples of the substituted or unsubstituted phenoxy group include phenoxy group, 2-methylphenoxy group, 3-methylphenoxy group, 4-methylphenoxy group, 2-ethylphenoxy group, 3-ethylphenoxy group, 4-ethyl. Examples include phenoxy group, 2,4-dimethylphenoxy group, 3,4-dimethylphenoxy group, 4-t-butylphenoxy group, 4-aminophenoxy group, 4-dimethylaminophenoxy group, 4-diethylaminophenoxy group and the like.

  Specific examples of the substituted or unsubstituted naphthoxy group include 1-naphthoxy group, 2-naphthoxy group, nitronaphthoxy group, cyanonaphthoxy group, hydroxynaphthoxy group, methylnaphthoxy group, trifluoromethylnaphthoxy group and the like. .

  Specific examples of the substituted or unsubstituted phenylthio group include a phenylthio group, a 2-methylphenylthio group, a 3-methylphenylthio group, a 4-methylphenylthio group, a 2-ethylphenylthio group, and a 3-ethylphenylthio group. Group, 4-ethylphenylthio group, 2,4-dimethylphenylthio group, 3,4-dimethylphenylthio group, 4-t-butylphenylthio group, 4-aminophenylthio group, 4-dimethylaminophenylthio group , 4-diethylaminophenylthio group and the like.

  Specific examples of the substituted or unsubstituted naphthylthio group include 1-naphthylthio group, 2-naphthylthio group, nitronaphthylthio group, cyanonaphthylthio group, hydroxynaphthylthio group, methylnaphthylthio group, trifluoromethylnaphthylthio group. Etc.

  X may be a combination of two or more compounds (for example, a compound having a 1,3,5-triazine ring and a compound having a porphyrin skeleton).

  As the polymerizable liquid crystal compound, a rod-like liquid crystal molecule or a discotic liquid crystal molecule can be applied, and a discotic liquid crystal molecule is particularly preferable. As the rod-like liquid crystalline molecules, liquid crystalline molecules described in JP-A-2006-16599 can be employed. For example, azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoates, cyclohexanecarboxylic acid Phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolanes and alkenylcyclohexylbenzonitriles are also used. As the discotic liquid crystalline molecules, for example, those described in JP-A-8-27284 can be used. An example is shown below.

前記において、Ｙは、アルキレン基、アルケニレン基、アリーレン基、−ＣＯ−、−ＮＨ−、−Ｏ−、−Ｓ−およびそれらの組み合わせからなる群より選ばれる二価の連結基、および該二価の基を少なくとも二つ組み合わせた基であることが最も好ましい。
アルキレン基の炭素原子数は、１〜１２であることが好ましく、アルケニレン基の炭素原子数は、２〜１２であることが好ましく、アリーレン基の炭素原子数は、６〜１０である
ことが好ましい。
アルキレン基、アルケニレン基およびアリーレン基は、置換基（例、アルキル基、ハロゲン原子、シアノ、アルコキシ基、アシルオキシ基）を有していてもよい。
Ｒは、前記不飽和重合性基または官能基または熱重合性基から選ばれる少なくとも一つ以上の架橋性基、もしくは該架橋性基で置換されたアルキル基、アルケニル基、アリール基または複素環基である。

In the above, Y represents a divalent linking group selected from the group consisting of an alkylene group, an alkenylene group, an arylene group, -CO-, -NH-, -O-, -S-, and combinations thereof, and the divalent group. Most preferably, the group is a combination of at least two groups.
The alkylene group preferably has 1 to 12 carbon atoms, the alkenylene group preferably has 2 to 12 carbon atoms, and the arylene group preferably has 6 to 10 carbon atoms. .
The alkylene group, alkenylene group and arylene group may have a substituent (eg, alkyl group, halogen atom, cyano, alkoxy group, acyloxy group).
R represents at least one crosslinkable group selected from the unsaturated polymerizable group, functional group or heat polymerizable group, or an alkyl group, alkenyl group, aryl group or heterocyclic group substituted with the crosslinkable group. It is.

Moreover, the following can be used suitably as a polymerization composition formed by reacting styrene with a non-aromatic polyvalent carboxylic acid-containing monomer.
That is, it is obtained by reacting styrene with a non-aromatic polyvalent carboxylic acid-containing monomer, and has a weight average molecular weight of 30000 or less and a solid content acid value of 10 to 150 mgKOH / g.
In such a polymerization composition, a method well known to those skilled in the art, such as radical copolymerization of an ethylenically unsaturated group of styrene and an ethylenically unsaturated group of a non-aromatic polyvalent carboxylic acid-containing monomer in an organic solvent. By making it react, the polymerization composition whose weight average molecular weight is 30000 or less and whose solid content acid value is 10-150 mgKOH / g can be obtained.

  Thus, when a photosensitive coloring composition is prepared by blending a polymerization composition in which the weight average molecular weight is 30000 or less or the solid content acid value is controlled to 10 to 150 mgKOH / g, the conventional weight average molecular weight is 30000 or more, or Problems when using a photosensitive coloring composition containing a styrene-containing polymerization composition having a solid content acid value other than 10 to 150 mgKOH / g, that is, the alkali developability of the photosensitive coloring composition is deteriorated, and the development speed is moderately increased. The effect of the styrene-containing polymerization composition can be sufficiently exhibited without causing adverse effects such that the development time cannot be adjusted and the development time becomes long, or the development speed is too high and the coating film is easily peeled off from the substrate. It becomes possible. Furthermore, since it has a styrene content of 75 mol% or more, when a photosensitive coloring composition is prepared by blending a polymerization composition having a styrene content of 75 mol% or more as described above, the negative compound of a conventional styrene resin is included. It becomes possible to express refraction, and there is a problem that has occurred in the color layer of the alkali development type photosensitive color filter, that is, unnecessary about 2 to 30 nm caused by the influence of pigments, dispersants, and other binder resins. It is possible to cancel the positive thickness direction retardation value Rth and further reduce it to a negative value. Thereby, it is possible to provide a liquid crystal display device that can have an originally desired thickness direction retardation value of -20 to 50 nm and that has good display characteristics even when viewed obliquely. When the styrene content is less than 75 mol%, the positive thickness direction retardation value Rth of 2 to 30 nm cannot be sufficiently canceled, and the function as a birefringence adjusting agent cannot be exhibited.

The polymerization composition has sufficient heat properties, adhesion to the substrate, hardness, solvent resistance, alkali resistance, and birefringence properties that the polymerization composition has, It is preferable to have a content of 3 to 60% in the solid content of the photosensitive coloring composition.
Non-aromatic polyvalent carboxylic acid-containing monomers suitable for use in the polymerization composition include, for example, acrylic acid, methacrylic acid, maleic acid, monoalkylmaleic acid, fumaric acid, monoalkylfumaric acid, itaconic acid, monoalkylitacon. An acid, crotonic acid, etc. are mentioned. Of these, acrylic acid and methacrylic acid are preferably used.

  Furthermore, this polymerization composition may be used individually by 1 type, and can also be used in combination of 2 or more type. Furthermore, the addition amount of the polymerization composition is not particularly limited, but is preferably 1 to 200% by weight, and preferably 5 to 100% by weight with respect to 100% by weight of the pigment. More preferably, it is most preferable to set it as 10 to 70 weight%.

  Next, a liquid crystal display device provided with the above color filter will be described.

FIG. 14 is a schematic cross-sectional view of a liquid crystal display device including a color filter according to an embodiment of the present invention. A liquid crystal display device 19 shown in FIG. 14 is a typical example of a TFT drive type liquid crystal display device for a notebook personal computer, and includes a pair of transparent substrates 20 and 21 that are arranged to be spaced apart from each other. Liquid crystal (LC) is enclosed.
The liquid crystal is aligned according to TN (Twisted Nematic), STN (Super Twisted Nematic), IPS (In-Plane Switching), VA (Vertical Alignment), OCB (Optically Compensated Birefring), etc.
A TFT (thin film transistor) array 22 is formed on the inner surface of the first transparent substrate 20, and a transparent electrode layer 23 made of, for example, ITO is formed thereon. An alignment layer 24 is provided on the transparent electrode layer 23. A polarizing plate 25 including a retardation film is formed on the outer surface of the transparent substrate 20.
On the other hand, a color filter 26 as shown in FIG. 12 or 13 is formed on the inner surface of the second transparent substrate 21. Red, green and blue colored pixels constituting the color filter 26 are separated by a black matrix (not shown). A transparent protective film (not shown) is formed so as to cover the color filter 26, and a transparent electrode layer 27 made of, for example, ITO is formed thereon, and the alignment layer 28 covers the transparent electrode layer 27. Is provided. A polarizing plate 29 is formed on the outer surface of the transparent substrate 21. Note that a backlight unit 31 including a three-wavelength lamp 30 is provided below the polarizing plate 25.

  Hereinafter, although an example is given and described about an embodiment of the present invention, the present invention is not limited to the following example.

[Example 1]
(A) Preparation of red colored coating film 1 <Red colored composition 1>
A mixture having the following composition was uniformly stirred and mixed, then dispersed in a sand mill for 5 hours using glass beads having a diameter of 1 mm, and then filtered through a 5 μm filter to prepare a red pigment dispersion.
Red pigment (CI Pigment Red 254, “IRGAPHOR RED B-CF” manufactured by Ciba Specialty Chemicals, Inc. 7.9 parts Dispersant (“Ajisper PB821” manufactured by Ajinomoto Fine Techno Co., Ltd.) 1.8 parts Acrylic resin ( Solid content 20%) 36.5 parts Cyclohexanone 48 parts Thereafter, a mixture having the following composition was stirred and mixed so as to be uniform, and then filtered through a 5 μm filter to obtain a red colored composition 1.
42 parts of the dispersion 10 parts acrylic resin (solid content 20%) 10 parts trimethylolpropane triacrylate (Biscoat # manufactured by Osaka Organic Chemical Industry Co., Ltd.)
295) 4.8 parts Photopolymerization initiator ("Irgacure-369" manufactured by Ciba-Geigy) 2.8 parts Photosensitizer ("EAB-F" manufactured by Hodogaya Chemical Co., Ltd.) 0.2 parts Cyclohexanone 40.2 parts

The red coloring composition was applied to optical glass S-TIM22 (refractive index: 1.65) manufactured by OHARA Co., Ltd. by spin coating, and then prebaked at 70 ° C. for 20 minutes in a clean oven. Next, the substrate was cooled to room temperature and then exposed to ultraviolet rays using an ultrahigh pressure mercury lamp. Thereafter, the substrate was spray-developed using a sodium carbonate aqueous solution at 23 ° C., washed with ion-exchanged water, and air-dried.
Thereafter, post-baking was performed at 230 ° C. for 30 minutes in a clean oven to obtain each color coating film. The film thickness of the dried coating film was 2.0 μm in all cases.

(B) Retardation measurement retardation is 5 degrees from the direction inclined -45 degrees to 45 degrees from the normal direction of the substrate on which the coating film is formed using a transmission spectroscopic ellipsometer ("M-200" manufactured by JASCO Corporation). Measurement was performed at a wavelength of 610 nm in steps to obtain an ellipso parameter δ. A phase difference value Δ (λ) was calculated from Δ = δ / 360 × λ, and a retardation calculation value obtained from the equation (3) was curve-fitted using this value to calculate a three-dimensional refractive index.
Here using linear programming to curve fitting was determined n _x as error ρ of capital of the measured and calculated values of the formula (1) is minimized, n _y, n _z, a β . The obtained results are shown in Table 1. FIG. 10 is a graph in which retardation is plotted on the vertical axis and the incident angle is plotted on the horizontal axis. FIG. 11 shows the results of chromatic dispersion at wavelengths of 400 nm to 700 nm when irradiated at an angle of 45 degrees.

(C) Production of red colored films 2 to 5 On transparent substrates, optical glass S-TIM35 (refractive index 1.69), S-LAM60 (refractive index 1.74), S-LAH66 (made by OHARA Co., Ltd.) A red colored film 2 to 5 was obtained and evaluated in the same manner as in Example 1 except that a refractive index 1.77) and a glass substrate 1737 (refractive index 1.52) made by CORNING were used. The obtained results are shown in Table 1, the graph in which retardation is plotted on the vertical axis and the incident angle is plotted on the horizontal axis is shown in FIG. 10, and the results of chromatic dispersion at wavelengths of 400 nm to 700 nm when irradiated from 45 degrees obliquely are shown in FIG. Show.

  From Table 1, in the example using the optical glass having a refractive index of 1.65 to 1.77, the error was as small as 0.02 to 0.12, whereas the optical glass having a refractive index of 1.52 was used. In the example, it is as large as 0.252. Moreover, it can be seen from the graph showing the dependence of retardation on the incident angle (FIG. 10) that an example using optical glass having a refractive index of 1.65 to 1.77 shows a curve closer to the calculated value. As apparent from the chromatic dispersion graph of FIG. 11, the cause of this is that the wave swell due to multiple interference is reduced in the embodiment. This shows that the three-dimensional refractive index measuring method and measuring apparatus of the present invention are very excellent.

(D) Production of color filter 1 <Red coloring composition 2>
A red colored composition 2 was obtained in the same manner as the red colored composition 1 except that a melamine resin (“MX-750” manufactured by Nippon Carbide Industries Co., Ltd.) was used instead of the acrylic resin in the amount shown in Table 2.
The color filter 1 was produced by the method shown below.
First, the red coloring composition 2 was applied by spin coating to a glass substrate on which a black matrix had been formed in advance, and then prebaked at 70 ° C. for 20 minutes in a clean oven. Next, after cooling the substrate to room temperature, ultraviolet rays were exposed through a photomask using an ultrahigh pressure mercury lamp. Thereafter, the substrate was spray-developed using a sodium carbonate aqueous solution at 23 ° C., washed with ion-exchanged water, and air-dried. Further, post-baking was performed at 230 ° C. for 30 minutes in a clean oven to form striped red pixels on the substrate.

Next, using a green resist for color filter (CDP-GS6260 (Toyo Ink Manufacturing Co., Ltd.)), green colored pixels are formed in the same manner, and further a blue resist for color filter (CDP-BS6200 (Toyo Ink Manufacturing ( Co.))) was used to form blue colored pixels, and color filter 1 was obtained. The formed film thickness of each colored pixel was 2.0 μm.
Table 2 shows the results of measuring the Rth of each colored pixel produced from each color resist by the above method. Further, a retardation plate used in a liquid crystal display device, a thickness direction retardation value Rth of the liquid crystal material
And the Rth of the colored pixel layer, the Rth of the colored pixel layer is 50 nm for each of the red colored pixels when the color of the liquid crystal display device is minimized when viewed obliquely during black display. The green color pixel was 40 nm, and the blue color pixel was 20 nm.
Rth was evaluated according to the following criteria.
○: Rth is included in the range of ± 2 nm.
X: Not included in the above range.
The evaluation results are shown in Table 3.

(E) Production of liquid crystal display device An overcoat layer was formed on the obtained color filter, and a polyimide alignment layer was formed thereon. A polarizing plate was attached to the other surface of this glass substrate.
On the other hand, a TFT array and a pixel electrode were formed on one surface of another (second) glass substrate, and a polarizing plate was attached to the other surface.
The two glass substrates thus prepared face each other so that the electrode layers face each other, and are aligned using spacer beads while keeping the distance between both substrates constant, and the periphery is left so as to leave an opening for injecting the liquid crystal composition. Sealed with a sealant. A liquid crystal composition for VA was injected from the opening to seal the opening. The polarizing plate was provided with an optical compensation layer optimized to display a wide viewing angle. The liquid crystal display device thus fabricated was combined with a backlight unit to obtain a VA display mode liquid crystal panel.

(F) Visibility evaluation during black display of the liquid crystal display device The produced liquid crystal display device is displayed in black and leaks from the normal direction (substantially vertical direction) of the liquid crystal panel and from the direction (oblique) inclined by 45 ° from the normal direction. The amount of incoming light (orthogonal transmitted light; leakage light) was visually observed. Also, the chromaticity (u (、), v (⊥)) when viewed from a substantially vertical direction when displaying black and the chromaticity when viewed from an orientation inclined up to 60 ° from the normal direction of the display surface ( u (45), v (45)) were measured with Topcon BM-5A, the color difference Δu′v ′ was calculated, and the maximum value of Δu′v ′ at 0 ≦ Θ ≦ 60 ° was determined.

(Example 2, Comparative Examples 1-4)
<Blue coloring composition 1>
A mixture having the following composition was uniformly stirred and mixed, then dispersed in a sand mill for 5 hours using glass beads having a diameter of 1 mm, and then filtered through a 5 μm filter to prepare a blue pigment dispersion.
Blue pigment (CI Pigment Blue 15: 6, “LI” manufactured by Toyo Ink Co., Ltd.
ONOL BLUE ES ") 7.9 parts Dispersant (" Ajisper PB821 "manufactured by Ajinomoto Fine Techno Co., Ltd.) 1.8 parts Styrene resin (solid content 20%) 36.5 parts Cyclohexanone 48 parts Thereafter, a mixture having the following composition is uniformly formed After stirring and mixing as described above, the mixture was filtered through a 5 μm filter to obtain a blue colored composition 1.
42 parts of the above dispersion Styrene resin (solid content 20%) 10 parts Trimethylolpropane triacrylate (Biscoat # manufactured by Osaka Organic Chemical Industry Co., Ltd.)
295) 4.8 parts Photopolymerization initiator ("Irgacure-369" manufactured by Ciba-Geigy) 2.8 parts Photosensitizer ("EAB-F" manufactured by Hodogaya Chemical Co., Ltd.) 0.2 parts Cyclohexanone 40.2 parts

Color filters 2 to 4 were obtained in the same manner as in Example 1 except that the compositions shown in Table 2 were used for the photosensitive coloring composition and the retardation adjusting agent. A liquid crystal display device was produced using this color filter, and the same evaluation was performed.
Further, in Example 2 to Comparative Example 4, when the coloration of the liquid crystal display device when viewed obliquely during black display is minimized, the Rth of the colored pixel layer is 10 nm for each red pixel, It was 0 nm for green pixels and -20 nm for blue pixels.
The evaluation rank is as follows, and the results are shown in Table 3.
○: Δu′v ′ ≦ 0.04
×: Δu′v ′> 0.04

As shown in Examples 1 and 2, since the red color pixel, the green color pixel, and the blue color pixel of the color filter are formed so that Rth satisfies −20 nm to 50 nm, the obtained color filter is displayed on a liquid crystal display. By using it for a device, a liquid crystal display device having good visibility in an oblique direction can be obtained.
In Comparative Examples 1 and 2, since the Rth of the red colored pixel and the blue colored pixel are not formed so as to satisfy the range of −20 nm to 50 nm, the phase difference in the thickness direction of the red pixel, the green pixel, and the blue pixel is Since the balance is not good, color misregistration occurs in an oblique direction, resulting in poor visibility.
In Comparative Examples 3 to 4, when calculating Rth of the red colored pixel and the blue colored pixel, a plurality of transparent substrates having different refractive indexes described in the present invention are not used, and thus a deviation occurs from the design value of Rth. For this reason, color shift occurs in an oblique direction, resulting in poor visibility.
As described above, the retardation plate used in the liquid crystal display device, the thickness direction retardation value of the liquid crystal material, and the Rth of the color filter are combined so as to be an optimum value, thereby displaying black when viewed from an oblique direction. It is possible to provide a liquid crystal display device with no color and excellent visibility.

It is a schematic sectional drawing which shows the sample by which the thin film of 1 layer was formed on the transparent substrate. It is a figure which shows an example of the spectral transmission factor of the sample in which the thin film of 1 layer was formed on the transparent substrate. It is a graph which shows an example of the wavelength dispersion of the retardation in the incident angle of 45 degree | times of the sample in which the thin film of 1 layer was formed on the transparent substrate. It is a graph which shows the other example of the wavelength dispersion of the retardation in the incident angle of 45 degree | times of the sample in which the thin film of 1 layer was formed on the transparent substrate. It is a schematic block diagram which shows an example of the three-dimensional refractive index measuring apparatus which concerns on one embodiment of this invention. It is a graph which shows the retardation obtained by making polarized light obliquely inject into a sample from several diagonal incident angles including normal incidence, and a retardation calculation result for demonstrating the three-dimensional refractive index calculation method. It is a figure which shows an example of the refractive index ellipsoid of a sample for demonstrating the case (a) where the refractive index ellipsoid of a sample corresponds with Nx, Ny, and Nz in a reference coordinate system, and the case where it does not correspond (b). . It is a graph which shows the incident angle dependence of the retardation when the influence by multiple interference is not considered. It is a graph which shows the example of the incident angle dependence of retardation. It is a graph which shows the incident angle dependence of the retardation which concerns on one embodiment of this invention. It is a graph which shows the incident angle dependence of the retardation in a comparative example. It is a figure of the cross sectional view which shows an example of a color filter substrate. FIG. 6 is a cross-sectional view showing another example of a color filter substrate. It is sectional drawing explaining an example of a structure of a liquid crystal display device provided with a color filter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Glass substrate 2 ... Thin film 3 ... Light transmission state in thin film 4 ... Light transmission state in thin film considering multiple interference 5 ... Light source 6 ... Spectroscope 7 ... Polarizer 8 ... Sample stage 9 ... Analyzer 10 ... Detector 11 ... Data processing device 12 ... Display device 13 ... Glass substrate 14 ... Black matrix 15 .. Colored pixel 16... Counter substrate support layer 17... Cell gap control raising layer 18... Phase difference layer 19... Liquid crystal display device 20. ... TFT (Thin Film Transistor) array 23 ... Transparent electrode layer 24 ... Orientation layer 25 ... Polarizing plate 26 ... Color filter 27 ... Transparent electrode layer 28 ... Orientation layer 29 ... Polarizing plate 30 ... three-wavelength lamp 31 ... backlight unit

Claims (3)

At least for the colored composition layer formed on the transparent substrate,
1. Obtaining linearly polarized light perpendicularly to obtain an in-plane optical axis of the colored composition layer ;
2. The includes an optical axis and the step of obtaining the linearly polarized light traveling in a plane perpendicular to the colored composition layer is incident on the colored composition layer in at least three or more of the plurality of incident angles .phi.i and retardation R (φi),
3. The retardation R (.phi.i) and formulas R of formula _{(2) (φi; n x} , n y, n z, β) with, as ρ of the formula (1) is as small as possible, three-dimensional In determining the three-dimensional refractive index of the colored composition layer by applying a three-dimensional refractive index measurement method having the steps of determining refractive indices _nx , _ny , _nz , and β, reflection from the colored composition layer a transparent substrate such as rate is as small as possible, the by performing measurement of retardation R (.phi.i), the three-dimensional refractive index n _x, step n _y, shall be specified for n _z,
4). Step you form a colored composition layer was controlled in the range of -20 to + 50 nm thickness direction retardation of the colored composition layer based on the value of the three-dimensional refractive index,
A method for producing a color filter substrate , comprising:

(Here, i any integer in at least three or more ranges from _{1, n x, n y,} n z is three orthogonal components of the refractive index ellipsoid of the thin film, beta is definitive index ellipsoid sample xyz (An inclination angle with respect to each axial direction.)

(Where i, _nx , _ny , and _nz are the same as in equation (1). Also, in equation (2), θ is the angle of refraction of the polarized light in the sample, d is the film thickness of the sample, and β is (An inclination angle with respect to each axis direction of xyz in the refractive index ellipsoid of the sample.) A step of obtaining the retardation R of claim 1, wherein (.phi.i), for the same the colored composition layer formed on a transparent substrate of a different k pieces refractive index (k ≧ 2), successively retardation R _k ( φi), and for each φi, out of the k retardations R _k (φi), a retardation R _k (φi) corresponding to the transparent substrate having the minimum reflectance at φi is _{obtained as} R (φi The method for producing a color filter substrate according to claim 1, wherein: A transparent substrate satisfying | n ₂ −n ₁ | ≦ 0.1 is used, where n _{2 is} the refractive index of the transparent substrate, and n ₁ is the refractive index of the colored composition layer formed on the transparent substrate. Claim 1 characterized
Or the manufacturing method of the color filter board | substrate of Claim 2.

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